Grinding mill



Allg- 20, 1929'- A. E. G. MacCALLuM 1,725,715

GRINDING MILL Filed Nov. 19. 1928 Patented Aug. 2G, 1929.

UNITED STATES .ALFRED ERASMUS GEOFFREY MACCALLUM, OF WANDSWORTH, LONDON, ENGLAND.

GRINDING MILL.

Application filed November 19, 1928, Serial No. 320,473, and in Great Britain September 5, 1.927.

This invention relates to grinding mills for paint and like materials in which a number of grinding rollers are arranged with their axes parallel and in which the material to be ground is passed between one or more pairs of rollers and is subsequently caused to pass between a roller and a fixec grinding bar to complete the grinding operation.

The object of the present invention is to provide an improved method of mounting pairs of grinding rollers and to provide improved means for adjusting the positions of these rollers relatively the one to the other.

According to the invention a four roll grinding mill is provided wherein the meinbers of lower pair of rollers rotate about fixed axes and co-operate with a pair of rollers adjustable vertically as a pair relatively to the lower rollers and adjustable relatively the one to the other.

rlrceording` to another feature of the invention an upper pair of rollers is adjustable relatively to the lower pair rotatable about fixed axes in such a manner that the axes of the upper rollers move during adjustment through paths concentric with the axes of the respective lower rollers.

Reference will now be made to the accomp anying drawings which illustrate by way of example a four roll grinding mill constructed according to the invention and in which Figure 1 is an end elevation of the mill and Figure 2 is a sectional elevation of one of the end supports taken on the line 2-2 of Figure 1.

ln the form illustrated four rollers are arranged so that two rollers 1 and 2 rotate about axes in a plane above that of the axes of the lower pair of rollers 8 and 4. The upper rollers are in engagement the one with the other and each engages one of the lower rollers so that the material under treatment is caused to descend between the upper rollers and passes between the upper and lower rollers whilst the final grinding is imparted by grinding bars 5 held in adjustable relationship with the lower rollers 3 and 4 1n any suitable manner, and the ground product is removed by Scrapers 37 and collected in trays 38. r1`he lower rollers 8 and 4 rotate on shafts 6 and 7 carried in fixed bearings mounted in ond frame members 8 and the upper rollers 1 and 2 are carried in bearings,

hereinafter described, mounted in frames 9 mounted in guides formed in the main frame members 8 so as to be capable of vertical adjustment.

To the underside of each frame 9 and at the centre thereof is connected a rod 10 the lower end of which has screw threaded engagen'ient with the central boss of a worm wheel 11, this worm wheel being engaged by a worm 12 mounted on a. horizontal shaft 18 caried in bearings on the frame work 8 and provided with a hand wheel 14 for manual operation. The vertically slidable frame 9 is slotted as shown at 15 to accommodate bearings for the spindles 16 of the upper pair of rollers 1 and 2. Each bearing consists of fixed members 17 in which are slidably mounted bearing members 18 carrying the ends of the shaft 16. The bearing members 18 are formed externally and the bearing members 17 are formed internally with bearing surfaces concentric with the centres of rotation of the lower rollers 8 and 4, respectively, and the two bearing-members 18 are urged apart by plungers 19 between which is disposed a spring 20, the plungers 19 and spring 2O being housed in a member 21 of the sliding frame 9 which extends upwards between the bearings of the rollers 1 and 2.

The bearings for the upper rollers are held in position by a plate 22 which is secured by bolts 23 into the upper portion of the sliding frame 9 and upon the plate 22 is mounted a bearing 24 through which passes a shaft 25 which is so connected to the bearing that it is capable of rotational but not longitudinal movement with res sect thereto. The shaft 25 is provided at one or both ends with a hand wheel or wheels 26 and is also provided at its ends with oppositely screw threaded portions 27 and 28. These screw threaded portions engage sleeves 29 to which are pivotally connected links 81 whose lower ends are pivotally mounted to the upper portion of the frame work 8 at 82. The links 81 are pivoted between their ends to the outer ends of plungers 33 which are freely slidable through openings in the upper portion of the frame work 8 and enter sockets 34 in the sliding` frame work 9 in which plungers 35 are slidably mounted, the inner ends of these plungers 35 engaging the outer surfaces of the bearing elements 18. To allow for vertical adjustment of the frame 9 the inner endsA of the plunger-s 33 are tapered as shown at and are of such dimensions as to enter loosely the sockets 34. The mechanism above described is duplicated so that the upper rollers are adjustable at each end.

With the arrangement above described the upper rollers l and 2 can be adjusted towards or away from one another by operation of the hand wheel 26, movement of which in one direction forces the plungers 35 towards each other whilst'in the opposite direction the pressure on these plungers is slackened to allow the spring 20 to operate and move the bearings apart. The shape and mounting of the bearing members 18 ensures that in all adjustments the axes of the rollers l and 2 move in paths concentric with the axes of rotation of the rollersl 3 and 4f respectively.

I claim l. A grinding mill comprising a iframe work, a pair of lower rollers rotatable in. said framework on fixed axes, a frame vertically adjustable in said framework, a pair of upper rollers Jfor engagement, respectively, with said lower rollers, and a pair of bearings for the opposite ends of each of said upper rollers, said pairs of bearings being movable in said frame toward and away from one another inv arcs concentric, respectively, with the axes of the lower rollers.

2. A grinding mill according to claim l, including means for vertically adjusting the frame and means for moving the pairs of bearings toward and away from one another.

3. A grinding mill comprising a framework, a pair of lowerrollers rotatable in said framework, a pair of upper rollers to respectively engage said lower rollers, a frame vertically adjustable in said 'framework and having two oppositely directed pairs of guideways, each pair of which is curved on an arc concentric with the axis of rotation of one of said lower rollers, and a pair of bearings for the ends of eachV of said upper rollers, the pair of bearings for each upper roller being movable toward and away from the other pair of bearings in a pair or' said guidoways.

4. A grinding mill according to claim 3, comprising means tending to move the pairs ot' bearings away from one another and means for moving said bearings toward one another and securing them in adjusted position.

5. A grinding mill according to claim 3, comprising means tending to move the pairs ot bearings away from one another, means for moving said bearings toward one another and securing them in adjusted position, and means for vertically adjusting said frame.

6. A grinding mill according Vto claim l, including means for vertically adjusting the frame toward and away from the lower rollers.

In testimony whereof I have hereunto set my hand.

ALFRED ERASMUS GEOFFREY MacCALLUM. 

